Simulation of arc characteristics in molded case circuit breaker

This paper focuses on the numerical investigation of arc plasma behavior in a certain type molded circuit breaker. A 3-D simulation model based on the magneto-hydrodynamics theory is built and calculated. The basic arc parameters are described by the coupled equations of gas dynamics and electromagnetic field. By adopting a thin layer of nonlinear resistance elements to represent the voltage drop of plasma sheath, the arc splitting process is included. The detailed arc behaviors are presented and preliminarily discussed according to the calculated temperature and arc current distributions. Moreover, experiments are carried out to validate the simulation results. The arc voltage acquired by the numerical and experimental approaches shows good agreement.